As well known, FAT (File Allocation Table) is relatively uncomplicated and supported by virtually all existing operating systems, especially personal computers. As its name suggested, the most common implementation is the usage of a table which centralizes the information about which areas belong to files and are free or possibly unusable, and where each file is stored on a disk. The ubiquity makes it an ideal format for floppy disks, solid-state memory cards, and the like, as well as makes it easier to pose unprecedented threats to personal data security and privacy. There is a need, therefore, for an improved storage apparatus compatible with the FAT file system for ensuring the confidentility of the data/files stored therein while interconnected to external systems.
Referring now to FIG. 1, it illustrates a flowchart for implementing host-dependent behavior according to U.S. Pat. No. 7,100,160. The first step, represented by block 10, comprises a host-target device log-in process wherein the host and the target device, such as a disk array controller, exchange information on capabilities of each device and form a communication connection. During this log-in process, the host would provide its host designator to the target device. After successful login, the target is allowed to receive commands from the host, as represented by block 12. For any given received command, the target determines whether the execution of the command depends on the protocol of the host in block 15. This step could be performed by comparing the received command to a list of commands that have O/S dependent requirements. If the command executes without regard to the host protocol, the following steps are not performed and the routine is exited at block 18. If there is a match to an O/S dependent command, then the following steps are performed.
The next step in the process, represented by block 20, obtains the value of a mode parameter that defines the default O/S protocol. For example, this mode parameter could be set to default to a HPUX protocol for all worldwide names not listed in the table. A further step in the process, represented by block 30, comprises accessing the aforementioned table which stores host designators and O/S types associated therewith. The flowchart further includes the step, represented by block 40, of determining if there is a match of the host designator obtained during the log-in process in block 10, to a host designator in the table. If there is such a match to a host designator in the table, then the method operates to override the default mode parameter designation for the O/S protocol, and to select the O/S protocol associated with the matched host designator. This step is represented by block 50 in FIG. 1.
As discussed above, the prior art provides a method and system only to tackle with certain ambiguities and compatibility problems that heterogeneous hosts may cause, by selecting an appropriate protocol associated with the host, but overlooks that guarding the data from unauthorized leakage is the most high-profile issue. Hence, it needs to provide a storage apparatus with an effective security method to avoid the risk of unintended access to confidential data/files. Unlike conventional memory devices (such as the memory device of U.S. Pat. No. 7,100,160), the present invention does not act transparently or allow arbitrary access to private data/files, and solve the above problems.